One of Thalberg’s innovations was to have the brothers go out on tour to hone the sketches before filming commenced.  He felt the team’s comic effect had been dissipated in previous movies due to the piecemeal process of filmmaking.

Allan Jones – replacing Zeppo in the straight man/romantic lead role – sings ‘Alone’, the only hit from a Marx Brothers’ movie, with Nacio Herb Brown and Arthur Freed supplying music and lyrics respectively. 

The opera in question is Verdi’s Il Trovatore.

The MGM ‘Marxes’ were: A Night at the Opera (1935), A Day at the Races (1937), Room Service (1938), At the Circus (1939), Go West (1940) and The Big Store (1941).